Ahead of the Persian new year, Nowruz, Iranian Foreign Minister Javad Zarif strongly criticised United States sanctions on his country.

Iran will expand its ties with nations equally tired of "bullying" by the US, Zarif said on Wednesday, as Iranians mark the end of a year of an economic crisis fuelled by renewed US sanctions.

Ahead of the start of the new year in the Iranian calendar, Zarif called the sanctions "unprecedented, inhumane and illegal", and said Tehran would overcome the "medieval tactics" employed by Washington.

"We rely solely on our own people to overcome any challenges. But we also welcome constructive engagement, including with the expanding array of nations who are equally sick and tired of the bullying of the U.S.," Zarif said on his Twitter feed.

Last month, Zarif wrote on his Instagram page that he was resigning. However, Iranian President Hassan Rouhani rejected his resignation, saying it was against the national interests of the Islamic Republic.

Many in Iran & across the globe are tonight celebrating #Nowruz, the New Year. Nowruz means renewal: not only of nature, but of our thoughts, deeds, and— importantly—hope for a brighter future.
My thoughts on this happy occasion: https://t.co/K53T75xOS6

The United States reimposed sanctions on Tehran after US President Donald Trump chose last May to abandon Iran’s 2015 nuclear accord, negotiated with five other world powers.

The sanctions have helped weaken Iran's rial currency, which has fed into higher inflation.

The rial was trading at 135,000 per US dollar on the unofficial market on Wednesday, according to foreign exchange websites, three times weaker than a year ago, but off record lows around 190,000 per dollar were reached in late September.

France, Germany and Britain, which remain committed to the nuclear deal, opened a new channel for non-dollar trade with Iran in January to help shield business with Tehran against the US sanctions.

Also on Wednesday, Iranian leaders vowed to control soaring prices, bring stability to the national currency and create jobs as the nation marked the end of a year of economic crisis.

Iran's Supreme Leader Ayatollah Ali Khamenei said in a new year's speech that the Islamic Republic had successfully resisted the US sanctions, and called on the government to boost national production to face economic pressures.

"In the face of severe, and according to them unprecedented sanctions from America and Europe, the Iranian people showed a strong and powerful reaction both in the field of politics and economy," Khamenei said in a pre-recorded speech broadcast on state television.

Khamenei said: "The main problem in the country is the economic problem ... that is partly rooted in mismanagement."

Rouhani defended his record in a separate message broadcast immediately after that of Khamenei, saying economic problems were primarily caused by US sanctions.

“The new year is a year to boost production and create jobs for our dear young people," Rouhani said. "The new year is the year to control inflation, bring balance to the foreign currency market and expand friendship with neighbouring countries."